Carburetor



Aug. 27, 1929.

S. M. UDALE CARBURETOF Filed March 10, 2

Q QQQQ Q QQQ Q Q Q Patented Aug. 27, 1929.

PATENT OFFICE.

STANLEY IYIIAR'IINv UDALE, OF DETROIT, MICHIGAN, ASSIGNOR TO GEORGE E. HOL- LEY, or nnraorr, MICHIGAN.

I oannn'nnron.

Application filed March 10, 1924:- Serial No. 698,036.

T he object of this invention is to 'devisean improved variable ,Venturi carburetor adapted for aninternal combustion engine of the automobile type.'

The figure shows clearly in cross sectional elevation all the elements of the invention arranged (for the purpose of illustration) in one plane. i

In the figure A is the air entrance, B is the Venturi tube, G is a streamlined obstruction supported by the spring D and operated indirectly by the butterfly throttle G. H is a conventional float chamber adapted to maintain the fuel at a more or less constant level and having a restricted outlet I controlled by a needle valve J. K is a horizontal fuel passage leading to the main fuel nozzle L, which discharges into a primary mixture chamber N, O,'and P are rich'mixture outlets from M into the throat of the Venturi tube B. Q is the auxiliary air vented reservoir and S is the low speed tube communicating with the mixture outlets at T and U adjacent to and in advance of the throttle valve G.

The cylinder V in which the piston E reciprocates is provided with a restricted air vent W communicating with the atmosphere. 'llhe spring 1) is-su ported by a bracket X. The space between t e'throttle G and the obstruction G is lettered Y.

Operation.-When the throttle is first moved from the closed position the fuel outlets T U function in a well known manner. On further opening of G the piston E moves down because the atmospheric pressure acting on its upper surface is greater than the. pressure in Y. W being a #60 orifice.04" diameter, the travel downwards of E and C is relatively slow and steady.

Ltion.

Momentarilythere is created between C and B a zone of intense velocity resultihg in the violent aspiration of fuel through N from L. If the throttle is held in the position shown the engine speeds up and the obstruction moves down and air is admitted more freely, and the depression acting on L through N is reduced.

On again moving the throttle the depression again increases momentarily, this time opposite the passage 0, and the richness of the mixture is temporarily greater followedby a normal running mixture. In this way the tendency for the air to get ahead of the fuel'is checked and the reverse result is obtained.

As the obstruction C moves against the air stream it is possible to arrange a series of openings N, O, P, which are progressively uncovered or rather subjected to the engine suction. The function of the fuel well Q, and

vent R is too well known to require discussion at this date.

What I claim is In a carburetor, an air entrance, a mixture outlet, a Venturi tube, a fuel entrance therein comprising a plurality of fuel outlets,

a stream-lined obstruction-in said venturi located opposite said fuel entrance during normal operation, vacuum controlled means for -mov1ng the obstruction against the air flow,

whereby the fuel entrances are gradually and progressively subjected to the pressure existing in the venturi above the obstruc.

In testimony whereofhe affixes his signature.

STANLEY M. UDALE. 

